Is there life beyond Earth in our solar system?
Existe vida máis alá da Terra no noso sistema solar?
Wow, what a powerful question. You know, as a scientist -- planetary scientist -- we really didn't take that very seriously until recently.
Vaia, que pregunta máis poderosa. Saben, coma científicos, científicos planetario, non nos tomamos isto moi en serio, até fai pouco.
Carl Sagan always said, "It takes extraordinary evidence for extraordinary claims." And the claims of having life beyond Earth need to be definitive, they need to be loud and they need to be everywhere for us to be able to believe it.
Carl Sagan sempre dicía: "Alegacións extraodinarios esixen probas extraordinarias". E as probas de que existe vida máis alá da Terra teñen que ser definitivas, teñen que ser claras e teñen que estar en todas partes para que o poidamos crer.
So how do we make this journey? What we decided to do is first look for those ingredients for life. The ingredients of life are: liquid water -- we have to have a solvent, can't be ice, has to be liquid. We also have to have energy. We also have to have organic material -- things that make us up, but also things that we need to consume.
Entón, como facemos isto? Primeiro, o que deicimos facer é procurar os ingredientes da vida. Os ingredientes da vida son: auga en estado líquido, temos que ter un solvente, non pode ser xeo, ten que ser líquido. Tamén precisamos enerxía. Amais, necesitamos material orgánico, cousas que nos compón, mais tamén cousas que precisamos consumir.
So we have to have these elements in environments for long periods of time for us to be able to be confident that life, in that moment when it starts, can spark and then grow and evolve.
Entón, necesitamos ter estes elementos en ambientes e durante longos periodos de tempo para estar seguros de que a vida, no momento no que comeza, pode xurdir e entón crecer e evolucionar.
Well, I have to tell you that early in my career, when we looked at those three elements, I didn't believe that they were beyond Earth in any length of time and for any real quantity.
Ben, teño que lles dicir que nos comezos da miña carreira, cando procurabamos estes 3 elementos, non cría que estivesen máis alá da Terra en calquera tempo nin en calquera cantidade.
Why? We look at the inner planets. Venus is way too hot -- it's got no water. Mars -- dry and arid. It's got no water. And beyond Mars, the water in the solar system is all frozen.
Por que? Mirabamos para os planetas interiores. Venus é moi quente, non ten auga. Marte: seco e árido. Non ten auga. E máis alá de Marte, a auga no sistema solar está xeada.
But recent observations have changed all that. It's now turning our attention to the right places for us to take a deeper look and really start to answer our life question.
Mais observacións recentes mudaron todo isto. Agora a nosa atención está posta nos lugares correctos para que miremos máis a fondo e poidamos comezar a responder as nosas preguntas sobre a vida.
So when we look out into the solar system, where are the possibilities? We're concentrating our attention on four locations. The planet Mars and then three moons of the outer planets: Titan, Europa and small Enceladus.
Así, cando observarmos o noso sistema solar, cales son as posibilidades? Centramos a nosa atención en catro lugares. O planeta Marte e tres lúas de planetas externos; Titán, Europa e a pequena Encélado.
So what about Mars? Let's go through the evidence. Well, Mars we thought was initially moon-like: full of craters, arid and a dead world.
E que ten Marte? Vexamos as evidencias. Pensamos que Marte era coma a Lúa inicialmente: cheo de cráteres, árido e un mundo sen vida.
And so about 15 years ago, we started a series of missions to go to Mars and see if water existed on Mars in its past that changed its geology. We ought to be able to notice that. And indeed we started to be surprised right away. Our higher resolution images show deltas and river valleys and gulleys that were there in the past. And in fact, Curiosity -- which has been roving on the surface now for about three years -- has really shown us that it's sitting in an ancient river bed, where water flowed rapidly. And not for a little while, perhaps hundreds of millions of years. And if everything was there, including organics, perhaps life had started.
Entón, hai uns 15 anos, comezamos unha serie de misións a Marte para verificar se existiu auga en Marte que mudou a súa xeoloxía. Deberiamos poder advertir isto. E de feito comezamos a sorprendernos de novo. As imaxes de alta resolución amosaban deltas e vales de ríos e cañóns que estiveron aí no pasado. E de feito, Curiosity, que se está a mover pola superficie dende hai uns tres anos, amosounos que está no antigo leito dun río, onde a auga discorría rapidamente. E non durante pouco tempo, talvez durante centos de milleiros de anos. E se existiu algo aí, incluíndo material orgánico, talvez comezara a vida.
Curiosity has also drilled in that red soil and brought up other material. And we were really excited when we saw that. Because it wasn't red Mars, it was gray material, it's gray Mars. We brought it into the rover, we tasted it, and guess what? We tasted organics -- carbon, hydrogen, oxygen, nitrogen, phosphorus, sulfur -- they were all there.
Curiosity tamén furou o chan vermello e ensinou outros materiais. Emocionámonos moito cando vimos isto. Porque non era vermello Marte, era material gris, era gris Marte. Trouxemos isto, testámolo, e adiviñade que? Estabamos a testar material orgánico: carbono, hidróxeno, osíxeno, nitróxeno, fósforo, xofre, estaban aí.
So Mars in its past, with a lot of water, perhaps plenty of time, could have had life, could have had that spark, could have grown. And is that life still there? We don't know that.
Entón, Marte, no pasado, con moita auga, talvez con moito tempo, puido ter vida, puido ter esa chispa, puido crecer. E aínda está esa vida aí? Non o sabemos.
But a few years ago we started to look at a number of craters. During the summer, dark lines would appear down the sides of these craters. The more we looked, the more craters we saw, the more of these features. We now know more than a dozen of them.
Mais hai uns anos comezamos a mirar a unha serie de cráteres. Durante o verán, aparecían unhas liñas negras baixo estes cráteres. Canto máis mirabamos, máis cráteres viamos, e máis as tiñan. Agora coñecemos máis dunha ducia deles.
A few months ago the fairy tale came true. We announced to the world that we know what these streaks are. It's liquid water. These craters are weeping during the summer. Liquid water is flowing down these craters. So what are we going to do now -- now that we see the water? Well, it tells us that Mars has all the ingredients necessary for life. In its past it had perhaps two-thirds of its northern hemisphere -- there was an ocean. It has weeping water right now. Liquid water on its surface. It has organics. It has all the right conditions.
Hai uns meses o conto de fadas convertiuse en realidade. Anunciamos ao mundo que descubrimos que eran esas liñas. É auga, líquida. Eses cráteres pingan durante o verán. Auga líquida flúe nesos cráteres. Entón, que imos facer agora, agora que vemos a auga? Ben, dinos que Marte ten todos os ingredientes para a vida. No pasado probablemente dous terzos do hemisferio norte, eran océano. Ten auga goteando agora mesmo. Auga líquida na súa superficie. Ten materia orgánica. Ten todas as condicións necesarias.
So what are we going to do next? We're going to launch a series of missions to begin that search for life on Mars. And now it's more appealing than ever before.
Entón, que imos facer agora? Imos lanzar unha serie de misións para comezar a buscar vida en Marte. E agora é máis atractivo que nunca.
As we move out into the solar system, here's the tiny moon Enceladus. This is not in what we call the traditional habitable zone, this area around the sun. This is much further out. This object should be ice over a silicate core.
Cando avanzamos no noso sistema solar, aquí está a pequena lúa, Encélado. Non é o que chamaría unha zona habitable tradicional, esta área redor do sol. Iso está moito máis afastado. Este obxecto debería ser xeo sobre un núcleo de silicato.
But what did we find? Cassini was there since 2006, and after a couple years looked back after it flew by Enceladus and surprised us all. Enceladus is blasting sheets of water out into the solar system and sloshing back down onto the moon. What a fabulous environment. Cassini just a few months ago also flew through the plume, and it measured silicate particles. Where does the silica come from? It must come from the ocean floor. The tidal energy is generated by Saturn, pulling and squeezing this moon -- is melting that ice, creating an ocean. But it's also doing that to the core.
Mais que atopamos? Cassini estivo aí dende 2006, e despois duns anos mirou cara atrás despois de voar de Encélado e sorprendeunos a todos. Encélado está a tirar láminas de auga ao noso sistema solar e rebotando de novo cara a lúa. Que ambiente tan fabuloso. Hai uns meses, Cassini tamén voou sobre sobre unha columna, e mediu as partículas de silicato. De onde provén o sílice? Debe provir do chan do océano. Saturno xera a enerxía mareomotriz, empurrando e presionando esta lúa está derretendo o xeo, creando océanos. Mais tamén está a facer iso co núcleo.
Now, the only thing that we can think of that does that here on Earth as an analogy ... are hydrothermal vents. Hydrothermal vents deep in our ocean were discovered in 1977. Oceanographers were completely surprised. And now there are thousands of these below the ocean.
Agora, o único que podemos imaxinar que ten unha analoxía aquí na Terra... Son os respiradeiros hidrotérmicos. Os respiradeiros hidrotérmicos descubríronse en 1977 no noso océano. Os osceanógrafos estaban moi sorprendidos. E agora hai miles destes baixo o océano.
What do we find? The oceanographers, when they go and look at these hydrothermal vents, they're teeming with life, regardless of whether the water is acidic or alkaline -- doesn't matter. So hydrothermal vents are a fabulous abode for life here on Earth.
Que atopamos? Os oceanógrafos, cando observan estes respiradeiros hidrotérmicos, están cheos de vida, e non importa se a auga é aceda ou alcalina, non importa. Entón, os respiradeiros hidrotérmicos son unha fabulosa morada para a vida na Terra.
So what about Enceladus? Well, we believe because it has water and has had it for a significant period of time, and we believe it has hydrothermal vents with perhaps the right organic material, it is a place where life could exist. And not just microbial -- maybe more complex because it's had time to evolve.
Entón, que pasa con Encélado? Ben, cremos que como ten auga e tívoa durante moito tempo, e cremos que ten respiradeiros hidrotérmicos e quizais o material orgánico axeitado, pode ser un lugar onde existiu a vida. E non só microbiana, talvez máis complexa porque tivo tempo de evolucionar.
Another moon, very similar, is Europa. Galileo visited Jupiter's system in 1996 and made fabulous observations of Europa. Europa, we also know, has an under-the-ice crust ocean. Galileo mission told us that, but we never saw any plumes. But we didn't look for them.
Outra lúa, moi parecida, é Europa. Galileo visitou o sistema de Xúpiter en 1996 e fixo observacións fabulosas de Europa. Tamén sabemos que Europa ten un oceáno de cortiza baixo o xeo. A misión Galileo amosounos isto, máis nunca vimos ningunha columna. Máis tampouco as buscabamos.
Hubble, just a couple years ago, observing Europa, saw plumes of water spraying from the cracks in the southern hemisphere, just exactly like Enceladus.
Hubble, hai só uns anos, cando observaba Europa, viu columnas de auga que saían das fendas no hemisferio sur, exactamente coma Encélado.
These moons, which are not in what we call a traditional habitable zone, that are out in the solar system, have liquid water. And if there are organics there, there may be life.
Estas lúas, que non están no que normalmente chamamos unha zona habitable, que están fóra no sistema solar, teñen auga líquida. E si hai material orgánico aí, pode haber vida.
This is a fabulous set of discoveries because these moons have been in this environment like that for billions of years. Life started here on Earth, we believe, after about the first 500 million, and look where we are. These moons are fabulous moons.
É unha serie de descubrimentos fabulosos porque estas lúas estiveron neste ambiente así durante miles de millóns de anos. A vida comezou na Terra, cremos, despois dos primeiros 500 millóns, e mira onde estamos. Estas lúas son fabulosas.
Another moon that we're looking at is Titan. Titan is a huge moon of Saturn. It perhaps is much larger than the planet Mercury. It has an extensive atmosphere. It's so extensive -- and it's mostly nitrogen with a little methane and ethane -- that you have to peer through it with radar.
Outra lúa á que observamos é Titán. Titán é unha lúa xigante de Saturno. É, quizais, moito máis grande que o planeta Mercurio. Ten unha atmosfera enorme. É moi grande, e é na súa maioría nitróxeno cun chisco de metano e etano, que se precisa dun radar para observala.
And on the surface, Cassini has found liquid. We see lakes ... actually almost the size of our Black Sea in some places. And this area is not liquid water; it's methane. If there's any place in the solar system where life is not like us, where the substitute of water is another solvent -- and it could be methane -- it could be Titan.
E na superficie, Cassini atopou líquido. Vemos lagos... Case do tamaño do mar negro nalgúns lugares. E esta área non é auga líquida; é metano. Se hai algún lugar no sistema solar onde a vida non é coma nós, onde o sustituto da auga é outro solvente, e poida ser o metano, podería ser Titán.
Well, is there life beyond Earth in the solar system? We don't know yet, but we're hot on the pursuit. The data that we're receiving is really exciting and telling us -- forcing us to think about this in new and exciting ways. I believe we're on the right track. That in the next 10 years, we will answer that question. And if we answer it, and it's positive, then life is everywhere in the solar system. Just think about that. We may not be alone.
Ben, hai vida máis alá da Terra no noso sistema solar? Aínda non o sabemos, máis sempre estamos na busca. Os datos que recibimos nos entusiasman e nos din, fannos pensar nesto en novos xeitos. Creo que estamos no camiño correcto. Que en 10 anos responderemos esa pregunta. E se a respondemos, e é un si, significará que a vida está en todo o sistema solar. Pensen nisto. Talvez non estamos sós.
Thank you.
Grazas.
(Applause)
(Aplausos)